1. Field of the Invention
This invention relates to a connection device and, more particularly, to a connection device used for connection between a sound source and a reproducing device employing a tape cassette.
2. Description of the Related Art
There has so far been proposed a connection device for transmitting information signals from an external equipment to a magnetic head of a magnetic tape reproducing device, such as a so-called cassette tape player. Such connection device is used for reproducing information signals outputted by a portable optical disc player, that is, acoustic signals of an optical disc, using, for example, a car-laden cassette tape player device, referred to herein as a car stereo device, as disclosed for example in U.S. Pat. Nos. 4,7348,97 and 5,444,675.
This connection device has a casing which is formed for being loaded on the car stereo device. This casing is shaped similarly to a casing of a tape cassette used as a signal recording medium for the car stereo device. That is, the casing of the connection device is loaded by an operation similar to the operation of loading a tape cassette on the car stereo device.
In the casing of the connection device is enclosed a signal transmitting head electro-magnetically coupled to a magnetic head of the car stereo device for transmitting information signals. Similarly to the magnetic head, this signal transmitting head has a core having a magnetic gap and a coil for generating a magnetic field within the magnetic gap. The coil of the signal transmitting head is connected to a connection cord pulled out of the casing. The foremost part of the connection cord carries a connection plug to be connected to a signal output terminal of an external acoustic equipment operating as a sound source, such as an optical disc player device. By connecting this connection plug to the signal output terminal of the external equipment and operating the external acoustic equipment, the information signals outputted by the external equipment are supplied to the coil of the signal transmitting head. The coil fed with the information signals from the external equipment are routed to the coil of the signal transmitting head. The coil, thus fed with the information signals from the external equipment, generates a magnetic field corresponding to the information signals within the magnetic gap.
When the casing is mounted on the car stereo device, the signal transmitting head and their magnetic head have the respective front surfaces abutted to each other, with the respective magnetic gaps substantially facing each other, so that a magnetic field corresponding to the information signals is generated in the magnetic gap of the signal transmitting head for transmitting the information signals to the magnetic head. Specifically, with the magnetic head, the magnetic field generated in the magnetic gap of the signal transmitting head operates similarly to the magnetic field transmitted by a magnetic tape carrying the recorded signals when the magnetic tape runs in contact with the magnetic head. The result is that output signals of the magnetic head are processed by the car stereo device in the same way as in reproducing a usual tape cassette and outputted as audible sound from a speaker of the car stereo device.
In such connection device, the signal transmitting head needs to be positively contacted with the front surface of the magnetic head for reliably transmitting the information signals to the magnetic head. This signal transmitting head cannot transmit the information signals optimally to the magnetic head unless the magnetic gap of the signal transmitting head substantially faces that of the magnetic head.
Even if the mounting position of the magnetic head in the car stereo device is within a pre-set tolerance, such position differs slightly from one product to another. Thus, even if the signal transmitting head is mounted with accurate positioning on the casing of the connection device, there are occasions wherein the signal transmitting head cannot be correctly abutted against the magnetic head when loading the cassette on the car stereo device, depending on the difference of the magnetic head mounting position from one car stereo device to another.
Therefore, in some of the connection devices, means are provided for enabling the user to make manual adjustment of the position of the signal transmitting head relative to the casing of the connection device.
In such connection device, the signal transmitting head is mounted on the casing via a position adjustment mechanism which permits the user to make some manual adjustment. In this position adjustment mechanism, the signal transmitting head is mounted for movement relative to the casing via a resilient member, such as a coil spring. This position adjustment mechanism is provided with a knob that can be actuated by the user from outside the casing. If, in this position adjustment mechanism, the adjustment knob is actuated manually by the user, the movement of the adjustment knob is transmitted to the signal transmitting head via a cam, thus modifying the state of abutment of the signal transmitting head against the magnetic head.
The user of the connection device actuates the signal transmitting head via the adjustment knob for manually finding the signal transmitting head position which will optimize transmission of the information signals from the signal transmitting head to the magnetic head.
With the above-described connection device, the position adjustment mechanism is provided for enabling position adjustment for varying the state of abutment of the signal transmitting head against the magnetic head. However, the device is complex in structure due to the provision of the position adjustment mechanism. The position adjustment mechanism requires an adjustment knob movably mounted on the casing, a cam connected to the adjustment knob, a head holder secured to the casing, a coil spring interposed between the head holder and the signal transmitting head or guide members for regulating the path of movement of the signal transmitting head. In addition, these components need to be mounted within the above casing.
In the above-described connection device, position adjustment of the signal transmitting head relative to the casing by the user is complex, while the possibility is high that the device be used in the absence of the correct adjustment or the user fail to perform the adjustment.